U.S. patent application number 10/705628 was filed with the patent office on 2004-08-05 for system and method for measuring a horizontal deviation of a load receiving element.
Invention is credited to Lukas, Gunther.
Application Number | 20040149056 10/705628 |
Document ID | / |
Family ID | 7683901 |
Filed Date | 2004-08-05 |
United States Patent
Application |
20040149056 |
Kind Code |
A1 |
Lukas, Gunther |
August 5, 2004 |
System and method for measuring a horizontal deviation of a load
receiving element
Abstract
The aim of the invention is to provide a system and a method
which surmounts the problems of prior art. According to the
inventive system and method for measuring horizontal deviation of a
load receiving element in relation to a position of a hoist
traveling trolley, the load receiving element is suspendedly
arranged on a plurality of supporting cables on said hoist
traveling trolley and least two cable length sensors are provided,
said sensors being operatively connected to a data processing
means, preferably a processor. The cables of the at least two cable
length sensors are disposed between the hoist traveling trolley and
the load receiving element in such a way that a computer unit which
is connected to the data processing means determines the horizontal
deviation of the load receiving element in relation to the position
of the hoist traveling trolley for the length of the respective
cables of the cable length sensors.
Inventors: |
Lukas, Gunther; (Parustein,
DE) |
Correspondence
Address: |
ST. ONGE STEWARD JOHNSTON & REENS, LLC
986 BEDFORD STREET
STAMFORD
CT
06905-5619
US
|
Family ID: |
7683901 |
Appl. No.: |
10/705628 |
Filed: |
November 10, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10705628 |
Nov 10, 2003 |
|
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PCT/EP02/05102 |
May 8, 2002 |
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Current U.S.
Class: |
73/865.9 ;
212/276; 702/113 |
Current CPC
Class: |
B66C 13/063
20130101 |
Class at
Publication: |
073/865.9 ;
702/113; 212/276 |
International
Class: |
B66C 013/16 |
Foreign Application Data
Date |
Code |
Application Number |
May 8, 2001 |
DE |
DE 101 22 142.8 |
Claims
1. System for measuring a horizontal deviation (A) of a load
receiving element (2) in relation to a position of a hoist
traveling trolley (1), wherein the load receiving element (2) being
suspendedly arranged on a plurality of supporting cables (10a, 10b,
10c, 10d) on the hoist traveling trolley (1) consisting of at least
two cable length sensors (3, 4) which are operatively connected to
a data processing means (S) and the cables (8, 9) of the at least
two cable length sensors (3, 4) are arranged between the hoist
travelling trolley (1) and the load receiving element (2) in such a
way that a computer unit which is connected to the data processing
means (S) determines the horizontal deviation (A) of the load
receiving element (2) in relation to a position of a hoist
travelling trolley (1) for the length of the respective cables (8,
9) of cable length sensors (3, 4).
2. System according to claim 1, wherein the cables (8, 9) of the at
least two cable length sensors (3, 4) are arranged in such a way
that the length of the cable (8) of the first cable length sensor
(3) decreases compared to the state without horizontal alignment
due to a horizontal deviation of the load receiving element, while
at the same time the length of the cable (9) of the second cable
length sensor (4) increases.
3. System according to claim 2, wherein the at least two cable
length sensors (3, 4) are arranged in such a way that their cables
(8, 9) are intersecting.
4. System according to claims 1 to 3, wherein at least one of the
cable length sensors (3, 4) is arranged on the hoist travelling
trolley.
5. System according to claims 1 to 3, wherein at least one of the
cable length sensors (3, 4) is arranged on the load receiving
element.
6. System according to any one of the aforementioned claims,
wherein the cable length sensors (3, 4) are not arranged on the
same side of the hoist travelling trolley (1) or the load receiving
element (2).
7. System according to any one of claims 1 to 6, wherein one of the
at least two cable length sensors (3) is arranged in a front part
of the hoist travelling trolley (1) and whose cable (8) essentially
extends diagonally to an anchorage point (5) to a rear part of the
load receiving element (2), whereas the other of the at least two
cable length sensors (4) is arranged at a rear part of the hoist
traveling trolley (1) and whose cable (9) essentially extends
diagonally to an anchorage point (6) in a front part of the load
receiving element (2).
8. System for measuring a horizontal deviation (A) of a load
receiving element (2) in relation to a position of a hoist
travelling trolley (1), wherein the load receiving element (2)
being suspendedly arranged on a plurality of supporting cables
(10a, 10b, 10c, 10d) on the hoist travelling trolley (1),
particularly using a system according to any one of the above
claims, consisting of the steps: Measurement of a first diagonal
distance between a rear part of the hoist travelling trolley (1)
and a front part of the load receiving element (2) and simultaneous
measurement of a second diagonal distance between a font part of
the hoist travelling trolley (1) and a rear part of the load
receiving element; Transmittal of the two measured values to an
electronic data processing means; Insertion of the two measured
values into a predetermined algorithm stored in a computer unit
connected to the electronic data processing means; Determination of
an initial value which is equivalent to the horizontal deviation
(A) of the load receiving element (2) in relation to the hoist
travelling trolley (1).
9. Method for measuring a horizontal deviation (A) of a load
receiving element (2) in relation to a position of a hoist
travelling trolley (1), wherein the load receiving element (2)
being suspendedly arranged on a plurality of supporting cables
(10a, 10b, 10c, 10d) on the hoist travelling trolley (1),
particularly using a system according to any one of the above
claims, consisting of the steps: Measurement of a first distance
between the rear part of the hoist travelling trolley (1) and a
central part of the load receiving element (2) and simultaneous
measurement of a second distance between a front part of the hoist
travelling trolley (1) and the central part of the load receiving
element; Transmittal of the two measured values to an electronic
data processing means; Insertion of the two measured values into a
predetermined algorithm stored in a computer unit connected to the
electronic data processing means; Determination of an initial value
which is equivalent to the horizontal deviation (A) of the load
receiving element (2) in relation to the hoist travelling trolley
(1).
10. Method according to claims 8 or 9, wherein the initial value is
an angular value (.alpha.).
11. Use of at least two cable length sensors, particularly
according to a method of claims 8 or 9, for measuring a horizontal
deviation (A) of a load receiving element (2) in relation to a
position of a hoist travelling trolley (1), wherein the load
receiving element (2) being suspendedly arranged on a plurality of
supporting cables (10a, 10b, 10c, 10d) on the hoist travelling
trolley (1) consisting of at least two cable length sensors (3, 4)
which are operatively connected to a data processing means (S) and
the cables (8, 9) of the at least two cable length sensors (3, 4)
are arranged between the hoist travelling trolley (1) and the load
receiving element (2) in such a way that a computer unit which is
connected to the data processing means (S) determines the
horizontal deviation (A) of the load receiving element (2) in
relation to a position of a hoist travelling trolley (1) for the
length of the respective cables (8, 9) of cable length sensors
(3,4).
Description
[0001] This application is a continuation of pending International
Patent Application No. PCT/EP02/05102 filed May 8, 2002, which
designates the United States and claims priority of pending German
Application No. 10122142.8 filed May 8, 2001.
[0002] The aim of the present invention is to provide a system from
a horizontal deviation of a load receiving element in relation to a
position of a hoist travelling trolley, wherein the load receiving
element being suspendedly arranged on a plurality of supporting
cables on the hoist travelling trolley, as well as a method for
measuring a horizontal deflection of a load receiving element in
relation to a position of a hoist travelling trolley, wherein the
load receiving element being suspendedly arranged on a plurality of
supporting cables on the hoist travelling trolley.
[0003] During the transportation of loads by bridge crane or gantry
crane, ship unloader, girder bridge cranes, as well as coil and
steel store gantry cranes, loads are regularly lifted from a
location A at a level of h.sub.0 to a transport level of h.sub.1,
whereupon they are transported to a destination B at a height of
h.sub.2 by a predetermined and normally time-optimized route.
[0004] In the case of all afore mentioned means of transport, a
so-called hoist travelling trolley is provided on a cross beam on
which, connected by supporting cables, load receiving elements such
as gripping devices for receiving loads, for example containers,
pallets and the like are arranged.
[0005] After receiving the load at location A, a horizontal
movement of the hoist travelling trolley is regularly effected,
wherein, due to the inertia, the loads suspended from the cables
are accelerated or respectively decelerated in relation to the
hoist travelling trolley in a delayed fashion. These acceleration
or deceleration processes lead to a horizontal deviation of the
load receiving element in relation to the position of the hoist
traveling trolley. This deviation occurs regularly during
transportation of the loads suspended from the supporting cables,
with the consequence that an undesirable oscillation of the loads
attached to the supporting cables will be initiated during a steady
movement of the hoist traveling trolley.
[0006] One of the constant tasks of a crane operator, therefore, is
to counteract these oscillatory movements. A practised and
attentive crane operator will achieve this through skillful
countersteering during the transport movement. If, however, the
operator is unpractised or unattentive, the tranportation
operations and handling times may be considerably extended. In the
worst case, there will be a higher risk of collisions and
accidents.
[0007] There are known oscillation damping devices by CePLuS in
Magdeburg which use high-performance cameras with microprocessors
for measuring a horizontal deviation of the load receiving element.
These high-performance cameras are mounted to a hoist travelling
trolley and measure the movements of the loads so they can adapt
the velocity of the hoist travelling trolley while traversing in
order to prevent undesirable oscillation of the loads from
occurring.
[0008] Reflectors are attached to the load receiving element in
order to measure the deviation of the load receiving element. The
camera mounted on the hoist travelling trolley is directed
downwards, i.e. in the direction of the load receiving element, and
determines the position of the reflector relative to the hoist
travelling trolley. The deviation of the load receiving element is
computed from this position data for the reflector.
[0009] A drawback of the CeSAR system by CePLuS has been that the
time intervals for determining the deviation are too large for
realtime dynamic control, and further, the resolution with regard
to the accuracy of measurement of the camera measurement system is
insufficient to meet the demands of the realtime dynamic control.
In addition to this detrimental system data, the overall size of
the CeSAR oscillation damping system has proved to be
disadvantageous, since the reflectors which must be attached to the
load receiving element have unfavourable dimensions. A further
drawback of the CeSAR system is the limited field of view if at
least a certain degree of measurement accuracy is required to be
achieved, as the accuracy of measurement of the camera lens
correlates to the horizontal field angle. A large horizontal field
angle requires, therefore, a so-called wide angle lens which,
however, is detrimental to image resolution and, ultimately,
accuracy of measurement.
[0010] One more drawback of the CeSAR system is the frequency of
maintenance required by the optical devices. This is because during
usage in conventional storage environments, a certain degree of
contamination of the racks, goods to be and, consequently, the
means of transport is to be expected at regular intervals, with the
result that the optical devices, such as the camera lens, will have
to be cleaned frequently.
[0011] The aim of the present invention, therefore, is to provide a
system and a method which surmount the problems of prior art.
[0012] This aim is performed by a system according to the invention
with the characterstics of claim 1 and by a method with the
characteristics of claims 8 and 9 respectively.
[0013] In the case of a system according to the invention for
measuring a horizontal deviation of a load receiving element in
relation to a position of a hoist travelling trolley, wherein the
load receiving element being suspendedly arranged on a plurality of
supporting cables on the hoist travelling trolley, there are at
least two cable length sensors provided, which are operatively
connected to a data processing means, preferably a processor,
wherein the cables of the at least two cable length sensors are
disposed between the hoist travelling trolley and the load
receiving element in such a way that a computer unit connected to
the data processing means determines the horizontal deviation of
the load receiving element in relation to a position of a hoist
travelling trolley for the length of the respective cables of the
cable length sensor.
[0014] Particularly advantageous are the small dimensions of the
cable length sensors and their anchorage points, the high accuracy
of measurement and sampling rate as well as the high ease of
maintenance of the system according to the invention.
[0015] The method according to the invention for measuring a
horizontal deviation of a load receiving element in relation to a
position of a hoist travelling trolley, wherein the load receiving
element being suspendedly arranged on a plurality of supporting
cables on the hoist travelling trolley, involves the following
steps:
[0016] Measurement of a first diagonal distance between the rear
part of the hoist travelling trolley and a front part of the load
receiving element and simultaneous measurement of a second diagonal
distance between a front part of the hoist travelling trolley and a
rear part of the load receiving element;
[0017] Transmittal of the two measured values to an electronic data
processing means;
[0018] Insertion of the two measured values into a predetermined
algorithm stored in a computer unit connected to the electronic
data processing means;
[0019] Determination of an initial value which is equivalent to the
horizontal deviation of the load receiving element in relation to
the hoist travelling trolley.
[0020] The system according to the invention is based on the
realization that when using at least two cable length sensors which
are disposed respectively on the hoist traveling trolley and/or
respectively on the load receiving element, the horizontal
deviation of the load receiving element effectuates a shortening of
the length of cable in the case of at least one of the cable length
sensors, wherein this horizontal deviation effectuates a
lengthening of the length of cable in the case of at least one
other the cable length sensor. To this effect, the at least two
cable length sensors are advantageously disposed on the hoist
traveling trolley or respectively on the load receiving element in
such a way that the two cables of at least two of the cable length
sensors are intersecting.
[0021] Such an intersection of the at least two cables is achieved
by one of the at least two cable length sensors being arranged in a
front part of the hoist traveling trolley or the load receiving
element wherein the other of the at least two cable sensors is
arranged in a rear part of the hoist travelling trolley or the load
receiving element and the anchorage point of the respective cables
is extended in a diagonal fashion from the respective front part to
the respective rear part and from the hoist travelling trolley to
the load receiving element. With regard to this type of guying, it
is immaterial whether the cable length sensor is arranged on the
same side of the hoist travelling trolley or the load receiving
element, as long as at a least physical intersection can be
assured.
[0022] By this method of guying the at least two cables and the
cable length measurement of the cable length sensor according to
the invention, the horizontal deviation of the load receiving
element is exactly determined by using simple trigonometric
relationships stored in an algorithm in a computer unit.
[0023] As the angl of deviation is preferably required for further
calculations of the hoist travelling trolley/load receiving
element, the angle f deviation stretched between the verticals and
the supporting cables is determined in a second mathematical step,
which likewise involves using simple trigonometric relationships.
The angle of deviation can then be used as an input variable for
the subsequent calculations of the motion system of the travelling
trolley/load receiving element.
[0024] It has proved particularly advantageous for the two cable
length sensors to be arranged in such a way that a maximum possible
distance exists between the two cable length sensors. Such a
maximum distance produces the greatest possible difference in the
lengths of the two cables and therefore increases the accuracy of
the measurement result.
[0025] In a different embodiment of the system according to the
invention, the two cables are not intersecting, but form a physical
"V" shape, wherein the anchorage points of the respective cables
are advantageously arranged at the apex of the physical "V" shape.
Simple trigonometic relations are made in the same way in order to
calculate the horizontal deviation.
[0026] In addition to the initially mentioned range of application
of the prior art, there are also advantages in particular in using
the system according to the invention in high bay warehouse
systems.
[0027] A preferred embodiment of the present invention will be
explained in greater detail referring to the following figures:
[0028] FIG. 1 shows a preferred embodiment of the system according
to the invention;
[0029] FIG. 2 shows the system according to the invention of FIG. 1
in motion.
[0030] FIG. 1 shows a system according to the invention consisting
of a hoist travelling trolley 1 which is driven by a motor M for
the purpose of transportation on rail 11. The power supply to the
motor M is not shown. Motor M is controlled via a control unit S
which is operatively connected to the motor M, but need not
necessarily be arranged on the hoist travelling trolley. A data
processing means, preferably a processor with a computer unit in
which corresponding mathematical algorithms are stored, is
integrated in or at least connected to the control unit. In the
preferred embodiment shown in FIG. 1, there are arranged on the
hoist travelling trolley 1 two cabl length sensors 3,4 whos cables
8, 9 are stretched diagonally downwards towards the load receiving
element and are secured there at an anchorage point 5,6. The length
of cables 8 and 9 is essentially the same in the rest position in
FIG. 1 since, due to gravity, the load receiving element 2 is
suspended perpendicularly by supporting cables 10a and 10b below
the hoist travelling trolley, as well as by supporting cables 10c
and 10d, which are not shown. The length of the supporting cables
10c and 10d is also controlled via motor M or via a special
drive.
[0031] For measuring the length of cables, cable length sensors,
for example, made by TR Electronic GmbH, which have an absolute or
incremental encoder, are used.
[0032] When the hoist travelling trolley reaches a certain velocity
or acceleration value, the inertia causes to supporting cables 10c
and 10d to move against the direction of movement by a defined
value A which is equivalent to a certain angle .alpha.. FIG. 2
shows the movement position of the system according to the
invention at a certain time instant in which the hoist travelling
trolley has reached a velocity .nu.. As a result of the horizontal
deviation of load receiving element 2 by the amount A or
respectively the angle .alpha. a change in the length of cables 8
and 9 of cable length sensors 3 and 4 occurs. This change in the
lengths of the cables is measured by cable length sensors 3 and 4
and transmitted to the computer unit provided in electronic data
processing means S. After having processed mathematical algorithms,
the computer unit indicates the deviation A as a magnitude of
absolute deflection or, alternatively, the angle .alpha. as an
initial values. This value is then input into the control system to
control motor M where it is processed accordingly, for example to
suppress the oscillation of the load receiving element.
* * * * *